Silver halide color photographic materials (referred to hereinafter as color photosensitive materials) are processed after exposure by color development, desilvering and additional processing operations (i.e., additional processing steps) such as water washing and stabilization, for example.
In the color development process, the exposed silver halide grains are reduced by the color developing agent to form silver, and the oxidant of the developing agent which is formed reacts with couplers to form the image dyes.
In the subsequent desilvering process, the developed silver which has been formed in the development process is oxidized (bleached) to a silver salt by use of a bleaching agent which has an oxidizing action, and this silver salt is removed (fixed), together with the unused silver halide, with a fixing agent which forms soluble silver. Bleaching and fixing can be carried out independently as a bleaching process and a fixing process, or they can be carried out at the same time in a single process (a bleach-fixing process). Details of these processing operations have been described by James in The Theory of the Photographic Process, fourth Edition, 1977.
Various supplementary processes, such as water washing processes, stabilization processes, film hardening processes and stop processes, can be carried out in addition to the above mentioned color development and desilvering processes, if desired, in order to maintain the photographic and physical quality of the dye image, or in order to maintain processing stability.
The above mentioned processing operations are generally carried out using an automatic processor. In recent years, in particular, small scale automatic processors known as mini-labs have been installed in stores, and the availability of rapid processing services for the customer has become widespread.
Against this sort of background, strong demands have arisen in particular in recent years for more rapid processing, and a great increase in the speed of the bleaching process has become desirable.
However, the ethylenediaminetetraacetic acid ferric complex salts which have been used conventionally have a fundamental weakness in that they have a low oxidizing power, and although the use of, for example, bleaching accelerators (for example, the addition of the mercapto compounds disclosed in U.S. Pat. 1,138,842) provides some improvement, the target of rapid bleaching has not been attained.
Ferricyanide (red prussiate of potash), ferric chloride and bromates, for example, are known as bleaching agents with which rapid bleaching can be achieved, but environmental problems are associated with ferricyanide, handling problems such as metal corrosion occur with ferric chloride, and problems with the instability of the solution occur with bromates, so these materials are not widely used.
Hence, a bleaching agent which provides rapid bleaching, which has good handling properties, and which does not have problems with disposal of the waste liquids is desirable.
The 1,3-diaminopropanetetraacetic acid ferric complex salt bleaching agent has been disclosed recently as a bleaching agent which fulfills these requirements. Furthermore, carbamoyl-type chelating agent bleaching agents have been disclosed in JP-A-1-93740 (the term "JP-A" as used herein refers to a "published unexamined Japanese patent application")
However, these bleaching agents have problems in terms of performance, in that bleach fogging occurs during bleaching. The addition of buffers to the bleach has been disclosed as a means of reducing the extent of bleach fogging (see, for example, JP-A-1-213657), but the level of improvement achieved is unsatisfactory, and in the case of rapid processing where the color development is carried out in 3 minutes or less, in particular, the occurrence of pronounced bleach fogging arises because of the highly active developers which are used.
Moreover, there is a problem with increased staining on storage after processing when a processing solution which has a bleaching ability comprising 1,3-diaminopropanetetraacetic acid ferric complex salt is used.
Further, there is a problem with increased change of gradation due to increase in a magenta coloration at the color image portion on storage after processing when a processing solution which has a bleaching ability comprising 1,3-diaminopropanetetraacetic acid ferric complex salt is used.
Also, there is a problem with a failure of color restoration due to a leuco dye which is formed by a cyan dye of the color image portion when the bleaching time is further shortened even if a processing solution which has a bleaching ability comprising 1,3-diaminopropanetetraacetic acid ferric complex salt is used.
To replace these compositions and methods, improved processing compositions which have a bleaching ability and processing methods are desired.